The objectives are to investigate the mechanisms regulating distribution and movement of human erythrocyte membrane macromolecules bearing blood antigens and receptors. Gold-labeled antibodies and scanning electron microscopy (SEM) are used for these studies. Electrophoretic patterns of protein and glycoprotein bands of solubilized membranes of normal and abnormal erythrocytes, and of their vesicles will be studied and compared. Antigenic activities in the solubilized vesicle preparations will be identified with their respective electrophoretic bands by inhibitor studies. The effect on hemagglutination of membrane fluidization by drugs will be quantitated.